General
Triceratops literally means "Three-horned Face" and these massive dinosaurs roamed the plains in the western part of North America in the late Cretaceous period about 72-65 million years ago. Triceratops had 2 large horns over their eyes and another smaller horn just above the nose. The horns could be used as a defense against predators like the contemporary Tyrannosaurus Rex, but were possibly used in mating rivalry too. With its large horns and massive body the Triceratops was a formidable opponent, and it is easy to picture a Triceratops charging into its enemy like the rhinoceros does. This makes it one of the most popular dinosaurs ever discovered.

It was a member of the family of large horned, herding herbivores called Ceratopsians. The Ceratopsians were one of the last group of dinosaurs to evolve before the Cretaceous-Tertiary extinction. Besides Tricaratops, the Ceratopsians include Protoceratops, Centrosaurus, Chasmosaurus, Leptoceratops, Montanoceratops, Pachyrhinosaurus, Psittacosaurus and Styracosaurus.

Fossils
About 50 skulls and some partial skeletons have been found, mostly in western North America (Colorado, Wyoming and Montana) but also in Southwest Canada. The first Triceratops skull was found in 1888 and named by O.C. Marsh.

Anatomy
Triceratops was about 20-30 feet (6-9 m) long, 7-10 (2-3 m) feet tall, and weighed an impressive 6-12 tons. It was a relatively slow dinosaur with four short but sturdy legs. It had a bulky body and a short pointed tail. The large skull was up to 10 feet (3 m) long, which is one of the largest skulls ever discovered. A large neck frill of solid bone rimmed with bumps projected from the back of the skull. The two longer horns above its eyes was over 3 feet (1 m) long.

Diet and behavior
Triceratops was probably a herding animal, like the other Ceratopsians. This is supported by the finding of bone beds. Most likely they moved around in herds seeking the vegetation to support their huge appetites. The parrot-like beak with powerful jaws and columns of cheek teeth that worked like scissors was used to eat very tough vegetation.